Plain English Meaning

Pumps that pull oil that has already done its job lubricating the engine out of the bottom of the engine and send it back to the tank so it can be cooled and used again.

Full Definition

Pumps in a dry-sump engine oil system that draw used oil out of the engine sumps and return it to the external oil tank for cooling and reuse.

Context Anchor

Seen in aircraft engine oil system descriptions, especially when comparing oil systems that carry oil in a separate tank instead of storing it all inside the engine.

Derivation

From the Old French escouve, 'to sweep or clean out.' A scavenge pump 'sweeps out' the oil that has collected in the engine after lubricating the moving parts.

Why Pilots Care

Without working scavenge pumps, oil would pool inside the engine, starve the pressure pump, overheat, and risk engine damage.